package com.ruoyi.framework.websocket;

import java.util.concurrent.Semaphore;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;

import com.alibaba.fastjson2.JSON;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import static com.ruoyi.framework.websocket.WebSocketUsers.*;

/**
 * websocket 消息处理
 * @author ruoyi
 */
@Component
@ServerEndpoint("/websocket/message/{sid}")
public class WebSocketServer {
    /**
     * WebSocketServer 日志控制器
     */
    private static final Logger LOGGER = LoggerFactory.getLogger(WebSocketServer.class);

    /**
     * 默认最多允许同时在线人数100
     */
    public static int socketMaxOnlineCount = 50;

    private static Semaphore socketSemaphore = new Semaphore(socketMaxOnlineCount);

    private Long sid;

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("sid") Long sid) throws Exception {
        boolean semaphoreFlag = false;
        // 尝试获取信号量
        semaphoreFlag = SemaphoreUtils.tryAcquire(socketSemaphore);
        if (!semaphoreFlag) {
            // 未获取到信号量
            LOGGER.error("\n 当前在线人数超过限制数- {}", socketMaxOnlineCount);
            sendMessage(session, "当前在线人数超过限制数：" + socketMaxOnlineCount);
            session.close();
        } else {
            // 添加用户
            this.sid = sid;

            WebSocketUsers.put(sid, session);
            LOGGER.info("\n 建立连接 - sid - {}", sid);
            LOGGER.error("\n 当前人数 - {}", WebSocketUsers.getUsers().size());

            Message message = new Message();
            message.setTo((long) -1);
            message.setMsg(sid+"号已上线");

            sendMessageToAll(JSON.toJSONString(message));   // 群发
        }
    }

    /**
     * 连接关闭时处理
     */
    @OnClose
    public void onClose(Session session) {
        LOGGER.info("\n 关闭连接 - {}", session);
        // 广播下线信息
        Message message = new Message();
        message.setTo((long) -1);
        message.setMsg(sid+"号已下线");
        sendMessageToAll(JSON.toJSONString(message));   // 群发
        // 移除用户
        WebSocketUsers.remove(sid);
        // 获取到信号量则需释放
        SemaphoreUtils.release(socketSemaphore);
    }

    /**
     * 抛出异常时处理
     */
    @OnError
    public void onError(Session session, Throwable exception) throws Exception {
        if (session.isOpen()) {
            // 关闭连接
            session.close();
        }
        LOGGER.info("\n 连接异常 - {}", sid);
        LOGGER.info("\n 异常信息 - {}", exception);
        // 移出用户
        WebSocketUsers.remove(sid);
        // 获取到信号量则需释放
        SemaphoreUtils.release(socketSemaphore);
    }

    /**
     * 服务器接收到客户端消息时调用的方法
     */
    @OnMessage
    public void onMessage(String message, Session session) {

        Message msg = JSON.parseObject(message, Message.class);
        msg.setFrom(sid);

        if (Long.valueOf(msg.getTo()).equals("-1")) {
            System.err.println("全体广播");
            sendMessageToAll(JSON.toJSONString(msg));
        } else {
            sendMessageToUsers(msg.getTo(),JSON.toJSONString(msg));
        }
    }
}
